On the Internet, advertisements are often presented that are based on the content displayed on a webpage. The goal is to match the subject matter of the advertisement with the subject matter of the webpage's content. The subject matter of the advertisement is often determined based upon keywords that are submitted with and/or extracted from the textual content of the advertisement. The subject matter of a webpage's content is often automatically determined by a computer program that evaluates words and/or phrases within the textual content of the webpage. The subject matter of a visual media object, such as an image or a video, may not be automatically determined as readily, because the visual media object often lacks textual content. This makes it difficult to automatically match the subject matter of a visual media object with the subject matter of an advertisement.